Fabric winding-down or drawing-off mechanism for circular knitting machines



June 14, 1955 H. s. BURDETT 2,710,530

FABRIC WINDING-DOWN OR DRAWING-OFF MECHANISM FOR CIRCULAR KNITTING MACHINES Filed May 15, 1953 4 Sheets-Sheet 1 Inventor'- Attorney June 14, 1955 Filed May 15, 1953 H- S. BURDETT FABRIC WINDING-DOWN OR DRAWING-OFF MECHANISM FOR CIRCULAR KNITTING MACHINES 4 Sheets-Sheet 2 39 22 I 7 34 23 26 I 1 o I I B 6 #6: J 9 /'H I F p 3 r 4 7/ a [30 o J 5 Inventor Attorney H s. BURDETT 2,710,530

FABRIC WINDING-DbWN 0R DRAWING-OFF MECHANISM June 14,1955

FOR CIRCULAR KNITTING MACHINES v 4 Sheets-Sheet 3 Filed May 15, 1953 lnve nlor

A ltorney- 1m 1955 H. s. BURDETT FABRIC WINDING-DOWN OR DRAWING-OFF MECHANISM MACHINES FOR CIRCULAR KNITTING,

4 Sheets-Sheet 4 Filed May 15, 1953 Inventqr Attorney FABRIC WlNDlNG-DGWN JR DRAWING-OFF MECHANlSM FGR CIRCULAR KNITTING MACHINES Henry Sidney Bartlett, Knighton, England Application May 15, 1953, Serial No. 355,301

Claims priority, application Great Britain May I6, 1952 21 Claims. (Cl. 66-153) This invention relates to mechanism for winding-down or drawing-01f fabric as it is produced on circular knitting machines.

Although principally intended for application to circular knitting machines of the rotary needle cylinder type,

the invention may be applied to circular'knitting machines 1 of the stationary needle cylinder type.

Moreover, the invention concerns fabric winding-down or drawing-off mechanism of the kind including a pair of rollers which are urged towards one another in a manner enabling each to yield in relation to the other, and wherein the fabric is gripped between the rollers while the latter are rotated for drawing off the fabric as it is produced on the needles of the knitting machine. In a mechanism of this kind the wind-down or drawingoif rollers are accordingly permitted to separate to allow for differences in the thickness of the fabric produced.

As applied to a circular knitting machine of the rotary needle cylinder type the winding-down or drawing-off mechanism revolves bodily in unison "with the needle cylinder or cylinders while the rollers are turned in opposite directions about their own axes, but in a machine of the stationary needle cylinder type the Winding-down or drawing-off mechanism also remains stationary while the rollers are driven.

Now with a mechanism of the kind concerned in operation, each of the yieldably mounted rollers is required to assume various parallel and angularpositions with respect to the companion roller during passage of fabric between the rollers. Thus, in this way each such roller can readily adapt itself to, and compensate for, different thicknesses of fabric such, for example, as heel and toe pouches in hosiery, and assume an angular position, for instance when the fabric moves to one end of the rollers. But as a consequence of the rollers assuming these various positions there has heretofore been a tendency for the means whereby the said rollers are driven either to jam or bind or to be displaced to an extent suflicient adversely to affect the proper working of the mechanism.

The primary object of the present invention is to provide, in or for a circular knitting machine, a generally improved form of fabric winding-down or drawing-off mechanism of the kind referred-to which is so designed that to whatever extent either of the rollers is displaced out of parallel with respect to the companion roller, a normal working position of associated means for effecting rotation of the said displaced roller will be maintained.

Anotherobject of the invention is to simplify the construction of such mechanism (hereinafter for convenience referred to simply as winding-down mechanism), minimise multiplication of its component parts and thereby reduce the cost of its production.

A still further object is to provide an improved construction, arrangement and manner of operation of the roller-driving means in the mechanism whereby a substantially uniform and continuous tension is applied to the fabric being drawn off the needles of the machine,

Pat nted .J ne .14, 1955 and the mechanism is made self-compensating for differences in the gauge .of the machine and variations in the quality, i. e. the length, of the loops of stitches in the knitted fabric, as will be hereinafter described.

in the improved fabric winding-down mechanism con stituting this invention the trunnions on the two fabric winding-down rollers are mounted for rotation in bearing blocks fitted in suitably spaced side vframe components, the bearing block at one end of one of such rollers being pivoted in the adjoining side frame component, and the bearing block at the other ,end of the companion roller being similarly pivoted in the opposite side frame compo mer t.

The trunnions of each roller may be either integral with .or be constituted by the ends of a piudle of the said roller.

Means for transmitting an independent drive to each winding-down :roller are carried by the trunnion extending through thepivoted bearing block of that roller.

The bearing block of each roller remote from the corresponding pivoted bearing block is slidable in the relevant side frame componentand is subject to spring pressure urging the said roller into cooperative relationship with the companion roller.

The construction of :the improved, mechanism is, therefor such that the rollers, by virtue ,of displacement thereof about the axes .of the pivoted bearing blocks, and against and under the springaction, readily assume various parallel and angular positions with respect to one another. Thus, the rollers are either separable to a uniform extent throughout their lengths to draw elf uniformly thick fabric gripped between them or, if occasion demands, are separable at one end only of the pair. Moreover, during such displacements of either roller,

-" the end of the latter remote from its pivoted bearing block will move in an are having the axis of the said block as its cent-re. Accordingly, whilst the slidable bearing block ,of each roller is permitted a fair degree of lateral movement against and under the action of the relevant spring means, the permitted turning movements of the corresponding pivoted bearing block will be only. slight. Since, therefore, the aforementioned means for transmitting the drive to the rollers are carried by the pivoted bearing blocks, the bodily displacements of these means will be insufficient to upset the proper working thereof. I

Aetuaticn of the last mentioned means may conveniently be effected by relative rotation between the winding-down mechanism and an operating cam about the central axis of the circular knitting machine, the arrangement being such that the drive-transmitting means at opposite ends .of the mechanism will be maintained intheir correct working relation with respect to the centre line of the machine and hence also to the operating cam. notwithstanding the extent of displacement of the rollers one or each in relation to the other.

in order that the invention may be more clearly understood and readily carried into practical effect, a spe cific constructional form of the improved fabric windingdown mechanism as applied to a circular knitting ma chine of the rotary needle cylinder type will now be described, by way of example, with reference to the accompanying drawings, wherein,

Figure l is a general perspective view nism.

Figure 2 is an elevational view of the same as seen in the direction of the arrow A in Figure 11 Figure 3 is a plan view of the mechanism,

Figure 4 is a detail plan view illustratiugmore clearly the bearing blocks for 2116. vrollers,

Figure 5 is a vertical sectional view showing, more of the mechaa particularly, the drive-transmitting means in association with one of the two fabric winding-down rollers, and

Figure 6 is a general perspective view of the fabric winding-down mechanism illustrated in position on the knitting machine.

Like parts are designated by similar reference characters throughout the drawings.

Referring to the drawings it will be seen that the mechanism includes a pair of fabric winding-down rollers l and 2 each of which is provided at its opposite ends with trunnions 3 and 4 mounted for rotation in bearing blocks 5 and 6 fitted in side frame components 7 and 7 The bearing block 5 at one end of the roller 1 is pivoted in the adjoining side frame component 7, whilst the corresponding bearing block at the other end of the companion roller 2 is similarly pivoted in the opposite side frame component 7 The bearing blocks 6 of the rollers 1 and 2 are slidable laterally in the side frame components 7 and 7 and, as and for the purpose hereinafter to be described, are subject to spring pressure.

Each of these side frame components consists of a vertically disposed rectangular or mainly rectangular solid plate or block of metal in the upper edge of which is formed a rectangular recess 8. This recess is converted into a closed rectangular and horizontal opening by the attachment to the top edge of the plate or block of a straight bar 9. In the opening thus provided in each of the side frames 7 and 7 there are accommodated, side by side, as shown more clearly in Figure 3, the pivoted bearing block 5 at the appropriate end of one of the winding-down rollers and the laterally slidable bearing block 6 at the same end of the companion roller. Each pivoted bearing block 5 is provided at its upper and lower ends, as depictedin Figure 2, with axially aligned trunnions 10 disposed on a vertical axis a and mounted to turn in bearing holes-11 and 12 formed respectively in the corresponding recessed plate or block and in the bar 9 attached to the top thereof. Each slidable bearing block 6 is pressed by a compression spring 13, through the medium of a plunger P in a direction to urge the associated roller into co-operative relationship with respect to the companion roller. This spring 13, the strength of which is adjustable by means of a screw 14, is horizontally disposed and accommodated in a hole 15, formed in the relevant side frame component 7 or 7 The inner end of each slidable bearing block 6, moreover, is formed with upwardly and downwardly directed flanges 6a and 6b arranged forengagement respectively with the inner sides of the straight bar 9 and of the plate or block of the relevant side frame component 7 or 7 As clearly depicted in Figure 4, the faces of these flanges 6a and 6b in contact with the side frame component are made slightly convex to permit of movements of the slidable bearing block in the required arcuate path.

The two side frame components 7 and 7 in this particular example are arranged parallel to each other at diametrically opposed sides of a carrier ring 16 to which they are secured by screws 17 (Figure 5). The ring is in turn attached to the top of the conventional gear 18 through the medium of which the work drum 19 and the superimposed winding-down mechanism are rotated. As illustrated in Figure 6, the gear 18 is arranged in mesh with a pinion 20 secured to the lower end of a vertical shaft 2! adapted to be driven from the cylinder driving means.

The drive-transmitting means in association with each of the rollers 1 and 2 may, as shown, consist of a ratchet wheel 22 rigidly secured upon the outer reduced end 3a of the roller trunnion 3 extending through the relevant pivoted bearing block 5 and an associated spring-infiuenced pawl 23 which is pivoted at 24 upon a racking arm 25 freely mounted upon the said trunnion. Each racking arm is spring-controlled and constituted by one limb of a bell-crank 26 to the outer end of the other limb 27 of which is fitted a convex roller 28 arranged to contact an operating cam 29. This cam is fixed upon the bottom of a tray 30 serving to support the winding-down mechanism and in which the gear 18 is rotatably mounted. The pinion 20 is accommodated in an extension 31 of the tray 30 which latter forms a part of the framework of the knitting machine in the usual way. The cam 29 is vertically disposed and has an appropriately contoured upper edge over which the rollers 28 ride. The said cam, moreover, is curved and concentrically disposed with respect to the vertical axis of the knitting machine. Accordingly, as the winding-down mechanism and the operating cam 29 rotate relatively, the two racking arms 25 at opposite ends of the mechanism will be alternately oscillated to effect continuous, or substantially continuous, rotation of the winding-down rollers l and 2 in opposite directions.

The limb 27 of each of the bell cranks 26 furnished with a convex cam roller 28 is also fitted with an inwardly directed pin 32 (Figures 2 and 5) which works in an elongated opening 33 formed in the adjacent side frame component 7 or 7 and is arranged to be acted upon by a horizontally disposed plunger 34 backed by a compression spring 35 accommodated in a further hole 36 in the said component.

In the illustrated example, the operating cam 29 functions to impart to each racking arm 25 its idle stroke, against the action of the spring 35, reaction of the loaded spring, upon release of the said racking arm 25 by the cam 29, being relied on to impart a forward, 1'. e. operative drive-transmitting stroke, to the racking arm and so turn the associated ratchet wheel 22 to the extent re quired. In short, in this particular arrangement, the two ratchet wheels 22 at opposite ends of the respective rollers 1 and 2 are driven round simultaneously by springs. When a spring 35 has been loaded by the operating cam 29, through the medium of the relevant racking arm 25, and the latter has been released, the reacting spring will, of course, exert spring pressure on the corresponding winding-down roller and, if as is preferred and shown, the rollers are formed with interengageable longitudinal flutes 37, also on the companion roller. It will therefore be appreciated that a further advantage of providing the hereinbefore described pivoted bearing blocks 5, which turn only to a slight extent and are to all intents and purposes fixed so far as any lateral movement thereof is concerned, is that the relationship of each such pivoted block with the spring plunger 34 at the same end of the mechanism is maintained. Consequently, the periodic movements of either racking arm 25 to re-load the rele-, vant spring 35 will produce the same degree of compression each time-irrespective of the thickness of the fabric passing between the rollers. The construction is, there-v fore, such that although the springs 35 are re-loaded (reset) alternately, the re-loading only occupies a very small portion of one revolution of the machine. Consequently the rollers 1 and 2 are urged round together by the springs 35 for the major portion of each such revolution.

The springs 35 may be made readily adjustable by means of screws 38 to set the improved mechanism for use either on a fine or a coarse gauge knitting machine.

The described arrangement wherein the springs. 35 drive the ratchet wheels 22 and the latter and the pawls 23 transmit the drive is self-compensating according to the amount of knitted fabric coming off the machine. The flexibility of the improved mechanism, in fact, automatically compensates for variation in quality as well as for differences in the gauge of the machine. The springs 35 for driving forward the ratchet wheels are so set as to be sufliciently strong to apply the correct degree of pull on the fabric as it is being produced and drawn off the needles normally. If, however, less fabric than normal is being produced, the springs will not tend to exert a greater pull than is necessary. In the event of a load up, for instance resulting from a broken needle latch,

this circumstance the mechanism will stop working and the winding-down rollers 1 and 2 will remain stationary.

Now each time either of the racking arms is caused by the operating cam 29 to make an idle stroke as previously described, the spring pressure is momentarily relieved as a consequence of which, unless some special provision were made, there would be a tendency for the corresponding ratchet wheel v22 to follow the idle movement of the pawl 23 on the arm and so relieve the downward pull on the work. To prevent this reverse rotation, a spring-influenced back stop pawl 39 is provided in engagement with each ratchet wheel.

The teeth on the ratchet wheels 22 are relatively small so as to enable the mechanism readily to compensate for differences in the gauge of the machine. To quote a specific example: if each ratchet wheel is provided with fifty teeth, then on a coarse gauge machine the length of work produced for each revolution of the machine may be approximately equivalent to, say, two teeth on a ratchet wheel, whereas on a fine gauge machine the length of work may be equivalent to only one tooth or even to less than one tooth.

As will be understood, whenever the mechanism is in operation one or the other of the two compression springs will be functioning to drive forward the rollers i and 2 so that the latter will be continuously rotated, or substantially, so. In this regard, the two compression springs 3:5 are 180 out of phase with one another, and each spring is reloaded once per revolution of the machine. The operating cam 29 in this case is made relatively short so as to be quick-acting.

As previously mentioned, the two winding-down rollers 1 and .2 are preferably formed with intermeshing longitudinal flutes 37. The flutes are intermeshed to enhance and. make more positive the grip on the fabric. this. regard it will be appreciated that the mechanism would not function so well if the rollers were able to slip on the fabric.

The improved mechanism is encased by a flanged cover 4% adapted to seat within the tray 30.

An important advantage arising from the adoption of the improved construction is that each of the two roller assemblies, the two side frame components and the two pawl and ratchet devices can be of identical forms. There is accordingly no necessity to provide right-hand and left-hand components, and as a consequence economical mass production is made possible.

The invention is principally intended, without limitation in this respect, for circular knitting machines of the double axially opposed needle cylinder type as well as to single cylinder machines capable of producing stockings, socks, half nose and the like.

I claim:

1. For a circular knitting machine, fabric windingdown mechanism comprising, in combination, a pair of rollers each of which is provided at its ends with trunnions, means urging the said rollers towards one another in a manner enabling each to yield in relation to the other, means for rotating the rollers, spaced side frame components, and bearing blocks which are fitted in the said components and have the roller trunnions mounted for rotation therein, the bearing block at one end of one of the aforesaid rollers being pivoted in the adjoining side frame component, whilst the bearing block at the other end of the companion roller is similarly pivoted in the opposite side frame component.

2. Fabric winding-down mechanism according to claim 1, wherein the bearing block of each roller remote from the corresponding pivoted bearing block is slidable in the relevant side frame component and is subject to spring pressure urging the said roller into co-operative relationship with the companion roller.

3. For a circular knitting machine, fabric windingdown mechanism comprising, in combination, a pair of rollers each provided at its ends with trunnions, means urging the said rollers towards one another in' a manner en; abling each to yield in relation to the other, spaced side frame components, bearing blocks which are fitted in the said components and have the roller trunnions mounted for rotation therein, the bearing block at one end of, one of the aforesaid rollers being pivoted in the adjoining side frame component whilst the bearing block at the other end of the companion roller is similarly. pivoted in the opposite side frame component, and, carried by the trunnion extending through the pivoted bearing block of each winding-down roller, means for transmitting an independent drive to that roller.

4. A circular knitting machine which is equipped with fabric winding-down mechanism comprising, in combination, a pair of rollers each of which is provided at its ends with trunnions, spaced side frame components, hearing blocks which are fitted in the said components and have the roller trunnions mounted for rotation, therein; the bearing block at one end of one of the aforesaid rollers being pivoted in the adjoining side frame; component; whilst the bearing block, at the other end of the companion roller is similarly pivoted in the opposite side frame com.-' ponent, and the bearingblock of each roller remote from the corresponding pivoted bearing block being slidable in the relevant side frame component, springs arranged to: influence the slidable bearingblocks suchwise asito urge. the rollers towards one another in a manner enabling each to yield in relation to the other, means carried by the trunnion extending through the pivoted bearing block of each winding-down roller for transmitting an independent drive to that roller, an operating cam for actuat: ing the said drive-transmitting means,v and means for ef+ fecting relative rotation between this cam and the fabric winding-down mechanis-rnabout the central axis of the machine.

5. A circular knitting machine according'to claim- 4, wherein the fabric Winding-down mechanism is. secured to a gear at the top of a rotary work drum, and the op erating cam is fixed.

6. A circular knitting machine according to claim 4:, wherein the drive-transmitting means associated with each of the two winding-down rollers consists of a ratchet Wheel secured upon the trunnionv of that roller extend ing through the relevant pivoted bearing block, and a springdnfiuenced pawl which is, pivoted upon a racking; arm freely mounted upon the said trunnion.

7. A circular knitting machine according to claim, 6;. wherein each racking arm is spring-controlled and pro vided with a part arranged, to contact the operating cam,- so that as the winding-down mechanism and the operat ing cam rotate relatively, .the two racking arms. at op.- posite ends of the mechanism will be alternately oscillated to effect substantially continuous rotation: of the Winding-down rollers in, opposite directions.

8. A circular knitting machine according to claim 7; wherein each racking arm is constituted by onerlimb of a bell crank to the other limb of; which is fitted a roller; to contact the operating cam.

9. A circular knitting machine. which isjequipped with fabric winding-downmechanism comprising,,in combinai tion, a pair of rollers each of which is provided at its ends with trunnions, spaced side frame components, hearing blocks which are fitted in the said components and have the roller trunnions mounted for rotation therein, the bearing block at one end of one of the aforesaid rollers being pivoted in the adjoining side frame component, whilst the bearing block at the other end of the companion rollers is similarly pivoted in the opposite side frame component, and the bearing block of each roller remote from the corresponding pivoted bearing block being slidable in the relevant side frame component, springs arranged to influence the slidable bearing blocks suchwise as to urge the rollers towards one another in a manner enabling each to yield in relation to the other, means carried by the trunnion extending through the pivoted bearing block of each winding-down roller for transmitting an independent drive to that roller, the said drive-transmitting means consisting of a ratchet wheel secured upon the said trunnion, a racking arm freely mounted upon the same trunnion and a spring-influenced pawl which is pivoted upon the racking arm and arranged to'co-operate with the ratchet wheel, an operating cam for actuating the said drive-transmitting means, and means for effecting relative rotation between this cam and the fabric winding-down mechanism about the central axis of the machine.

10. A circular knitting machine according to claim 9, wherein a spring-influenced back stop pawl is provided in engagement with each ratchet wheel, for the purpose herein described.

11. A circular knitting machine according to claim 9, wherein a spring is provided and the operating cam functions to impart to each of the two racking arms in turn an idle stroke, against the action of the spring, reaction of the loaded spring, upon release of the said racking arm by the cam being relied on to impart an operative drivetransmitting stroke to the racking arm.

12. A circular knitting machine according to claim 11, wherein the springs for imparting operative drive-transmitting strokes to the racking arms are of the compression type and located in holes bored in the side frame components.

13. A circular knitting machine according to claim 12,

wherein each racking arm is constituted by one limb of a bell crank, and the appropriate end of each of said springs presses on a plunger arranged to be acted upon by a part on the corresponding bell crank.

14. A circular knitting machine according to claim 13, wherein the springs are adjustable, for the purpose herein described.

15. A circular knitting machine which is equipped with fabric winding-down mechanism comprising, in combination, a pair of rollers each of which is provided at its ends with trunnions, spaced side frame components,

bearing blocks which are fitted in the said components and have the roller trunnions mounted for rotation therein, the bearing block at one end of one of the aforesaid rollers being pivoted in the adjoining side frame component, Whilst the bearing block at the other end 'of the companion roller is similarly pivoted in the opposite side frame component, and the bearing block of each roller remote from the corresponding pivoted bearing block being slidable in the relevant side frame component, springs to influence the slidable bearing blocks suchwise -as to urge the rollers towards one another in a manner enabling each to yield in relation to the other, means carried by the trunnion extending through the pivoted bearing block of each winding-down roller for transmitting an independent drive to that roller, the said drivetransmitting means consisting of a ratchet wheel secured upon the said trunnion, a racking arm freely mounted upon the same trunnion and a spring-influenced pawl which is pivoted upon the racking arm and arranged to co-operate with the ratchet wheel, an operating cam for actuating the said "drive-transmitting means, means for effecting relative rotation between this cam and the fabric winding-down mechanism about the central axis of the machine, and, in association with each racking arm, a compression spring which is located in a hole bored in the appropriate side frame component, the operating cam functioning to impart to each of the two racking arms in turn an idle stroke, against the action of the associated compression spring and reaction of the loaded spring, upon release of the racking arm by the cam being relied on to impart an operative drive-transmitting stroke to the racking arm.

16. A circular knitting machine according to claim 15, wherein the two compression springs are out of phase with one another, each spring is loaded once per revolution of the machine, and the operating cam is relatively short so as to be quick-acting.

17. For a circular knitting machine, fabric windingdown mechanism comprising, in combination, a pair of rollers each of which is provided at its ends with trunnions, means for rotating the rollers, spaced side frame components each consisting of a vertically dis posed plate having in its upper edge a rectangular recess and a bar which is attached to the top edge of the plate and serves to convert the recess into a closed rectangular and horizontal opening, pairs of bearing blocks which are accommodated within the openings in the side frame components and have the roller trunnions mounted for rotation therein, the bearing block at one end of one of the rollers being pivoted in the adjoining side frame component whilst the bearing block at the other end of the companion roller is similarly pivoted in the opposite side component and the remaining two bearing blocks being slidable laterally within the respective components, and springs arranged to influence the slidable bearing blocks in such a manner as to urge the rollers towards one another.

18. Fabric winding-down mechanism according to claim 17, wherein each pivoted bearing block is provided at its upper and lower ends with axially aligned trunnions disposed on a vertical axis and mounted to turn in bearing holes formed respectively in the corresponding recessed plate and in the bar attached to the top thereof.

19. Fabric Winding-down mechanism according to claim 17, wherein the end of each slidable bearing block is formed with upwardly and downwardly directed flanges arranged for engagement respectively with the inner sides of the bar and of the relevant plate.

20. Fabric winding-down mechanism according to claim 19, wherein the faces of these flanges are made convex, for the purpose herein described.

21. Fabric winding-down mechanism according to claim 1, wherein the two rollers are formed with interengageable longitudinal flutes.

Raven et al. Oct. 3, 1939 Kent at al. Jan. 30, 1940 

